title: Deep parallel sequencing reveals conserved and novel miRNAs in gill and hepatopancreas of giant freshwater prawn.
abstract: MicroRNAs (miRNAs) are ~20-22 nucleotides, non protein-coding RNA regulatory genes that post-transcriptionally regulate many protein-coding genes, influencing critical biological and metabolic processes. While the number of known microRNA is increasing, there is currently no published data for miRNA from giant freshwater prawns, Macrobrachium rosenbergii (M. rosenbergii), a commercially cultured and economically important food species. In this study, we identified novel miRNAs in the gill and hepatopancreas of M. rosenbergii. Through a deep parallel sequencing analysis and an in silico data analysis approach, 327 miRNA families were identified from small RNA libraries with reference to both the de novo transcriptome of M. rosenbergii obtained from RNA-Seq and to miRBase (Release 18.0, November 2012). Based on the identified mature miRNA and recovered precursor sequences that form appropriate hairpin structures, three conserved miRNA (miR125, miR750, miR993) and 27 novel miRNA candidates encoding messenger-like non-coding RNA were identified. miR-125, miR-750, G-m0002/H-m0009, G-m0005, G-m0008/H-m0016, G-m0011/H-m0027 and G-m0015 were selected for experimental validation with stem-loop quantitative RT-PCR and were found to be coherent with the expression profile of deep sequencing data as evaluated with Pearson's correlation coefficient (r = 0.835178 for miRNA in gill, r = 0.724131 for miRNA in hepatopancreas). Using a combinatorial approach of pathway enrichment analysis and inverse expression relationship of miRNA and mRNA, four co-expressed novel miRNA candidates (G-m0005, G-m0008/H-m0016, G-m0011/H-m0027, and G-m0015) were found to be associated with energy metabolism. In addition, the expression of the three novel miRNA candidates (G-m0005, G-m0008/H-m0016, and G-m0011/H-m0027) were also found to be significantly reduced at 9 and 24 h post infection in M. rosenbergii challenged with infectious hypodermal and hematopoietic necrosis virus, suggesting a functional role of these miRNAs in crustacean immune defense.
authors.affiliation: Genomic Research and Breeding Laboratory, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia. tiantian3t@gmail.com
authors.forename: Tian Tian
authors.initials: TT
authors.lastname: Tan
authors.forename: Maoshan
authors.initials: M
authors.lastname: Chen
authors.forename: Jennifer Ann
authors.initials: JA
authors.lastname: Harikrishna
authors.forename: Norliana
authors.initials: N
authors.lastname: Khairuddin
authors.forename: Maizatul Izzah
authors.initials: MI
authors.lastname: Mohd Shamsudin
authors.forename: Guojie
authors.initials: G
authors.lastname: Zhang
authors.forename: Subha
authors.initials: S
authors.lastname: Bhassu
mesh_terms: D000818:Animals; D001483:Base Sequence; D005786:Gene Expression Regulation; D005880:Gills / Q000378:metabolism; D043143:Hepatopancreas / Q000378:metabolism; D059014:High-Throughput Nucleotide Sequencing; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D033541:Palaemonidae / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D059467:Transcriptome
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger
keywords: Immune response; Macrobrachium rosenbergii; Transcriptome; microRNA